Natural resources such as oil or gas residing in subterranean formations can be recovered by drilling a wellbore that penetrates reservoirs within a given formation. During the establishment of a wellbore, a number of fluids are delivered downhole depending on the requirements of the particular operation. Wellbore fluids may be circulated through various downhole tools emplaced within the wellbore, including drill strings, casings, coiled tubing, and the like.
When fluid bearing formations are composed of poorly consolidated sands and other granular material, there is a natural tendency for the material to move with formation fluids into the wellbore during hydrocarbon production. In such formations, problems may arise when sands and other materials compact around the receiving end of the production string and reduce the effective radius of the wellbore, decreasing well productivity. In addition, sand production in unconsolidated wellbores may also erode hardware, block tubulars, create downhole cavities, and may require intervention to separate sand from fluids before disposal at the surface. To avoid such complications, completion methods employed in sand-containing reservoirs often use measures to keep formation sand in place without restricting productivity.
Techniques for controlling sand displacement may include placement of a gravel pack to hold formation sand in place and prevent sand from entering production streams from open-hole oil and gas wells. In gravel pack operations, a steel screen may be placed in a wellbore and the surrounding annulus is packed with prepared gravel of a specific size designed to prevent the passage of formation sand while still allowing fluid to flow through the gravel, screen, and enter production piping. Gravel packing operations may generally stabilize the formation while causing minimal impairment to well productivity.